Stimuli, reinforcers, and behavior: An integration

We propose that a fundamental unit of behavior is the concurrent discriminated operant, and we discuss in detail a quantitative model of the concurrent three-term contingency that is based on the notion that an animal’s behavior is controlled to differing extents by both stimulus–behavior and behavior–reinforcer relations. We show how this model can describe performance in a variety of experimental procedures: conditional discrimination and matching to sample, both with and without reinforcement for responses that are traditionally identified as errors; conditional discrimination with more than two stimuli and choice alternatives; delayed matching to sample and delayed rein-forcement in matching to sample; second-order and complex conditional discrimination; and mul-tiple and concurrent schedules. Although the model is incomplete in its coverage, and may be incorrect, we believe that this conceptual approach will bear fruit in the development of behavior theory. Key words: discriminated operant, conditional discrimination, stimulus control, reinforcement, de-tection models, matching, discriminability An adequate formulation of the interaction between an organism and its environment must always specify three things: (1) the oc-casion upon which a response occurs, (2) the response itself, and (3) the reinforcing con-sequences. The interrelations among them are the contingencies of reinforcement. (Skin-ner, 1969, p. 7) With the specification of the three-term con-tingency quoted above, Skinner defined the The order of authorship is alphabetical. We thank all those who have made empirical and theoretical contri-butions to our understanding of this area over man